There are many animal watering devices which are in use at the present time. One disadvantage inherent in most of these watering devices is the fact that they will freeze over in the winter thus denying the animal access to water and necessitating a visit by the farmer in order to break through the ice and allow access to the water by the animal. In particularly cold weather, it may be necessary to make several visits per day and, of course, it is important to the health of the livestock that water be available when so desired.
Several proposals have been made to prevent the ice formation on watering apparatuses in the winter. One such proposal, contained in several publications but particularly described in U.S. Pat. No. 5,146,873 (Gray), allows for an electrical heating element to be positioned in the water compartment in order to heat the water and thus prevent ice formation. However, the use of electrical power to heat the element is not always possible due to the distance the animals may be located from a source of electricity. In addition, electricity near water, particularly where power is needed in the order of that required to heat the heating element, can be dangerous to the animals and, of course, electricity is expensive.
A second proposal, as contained in U.S. Pat. No. 4,440,112 (Lilyerd), includes a device to provide turbulence in the water within the water compartment, the turbulence thereby preventing the formation of ice. A device to produce turbulence, however, requires a source of power. The use of electricity to produce the turbulence has the same disadvantages described above in respect of the Gray patent and in the event the turbulence is to be produced by the supply of water, it necessitates continuous running of the water which could overflow the reservoir or, in any event, is needlessly wasteful.
An open top portion to allow access by an animal to water in the reservoir is described in U.S. Pat. No. 5,003,928. In this patent, an insulated and buoyant disk is utilised which floats in the water and which allows access by the animal to the water in the reservoir around the outside of the disk. While this reference may have some advantages and may, indeed, hinder the ice formation, its disadvantages to the watering animal are apparent.